From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx> The both create_file_dentry() and create_dir_dentry() takes a boolean parameter "lookup", as on lookup the inode_lock should already be taken, but for dcache_dir_open_wrapper() it is not taken. There's no reason that the dcache_dir_open_wrapper() can't take the inode_lock before calling these functions. In fact, it's better if it does, as the lock can be held throughout both directory and file creations. This also simplifies the code, and possibly prevents unexpected race conditions when the lock is released. Link: https://lkml.kernel.org/r/20231121231112.528544825@xxxxxxxxxxx Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode") Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> (cherry picked from commit bcae32c5632fc0a0dbce46fa731cd23403117e66) --- fs/tracefs/event_inode.c | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 56d192f0ead8..590e8176449b 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -347,15 +347,8 @@ create_file_dentry(struct eventfs_inode *ei, int idx, mutex_unlock(&eventfs_mutex); - /* The lookup already has the parent->d_inode locked */ - if (!lookup) - inode_lock(parent->d_inode); - dentry = create_file(name, mode, attr, parent, data, fops); - if (!lookup) - inode_unlock(parent->d_inode); - mutex_lock(&eventfs_mutex); if (IS_ERR_OR_NULL(dentry)) { @@ -453,15 +446,8 @@ create_dir_dentry(struct eventfs_inode *pei, struct eventfs_inode *ei, } mutex_unlock(&eventfs_mutex); - /* The lookup already has the parent->d_inode locked */ - if (!lookup) - inode_lock(parent->d_inode); - dentry = create_dir(ei, parent); - if (!lookup) - inode_unlock(parent->d_inode); - mutex_lock(&eventfs_mutex); if (IS_ERR_OR_NULL(dentry) && !ei->is_freed) { @@ -693,6 +679,7 @@ static int dcache_dir_open_wrapper(struct inode *inode, struct file *file) return -ENOMEM; } + inode_lock(parent->d_inode); list_for_each_entry_srcu(ei_child, &ei->children, list, srcu_read_lock_held(&eventfs_srcu)) { d = create_dir_dentry(ei, ei_child, parent, false); @@ -725,6 +712,7 @@ static int dcache_dir_open_wrapper(struct inode *inode, struct file *file) cnt++; } } + inode_unlock(parent->d_inode); srcu_read_unlock(&eventfs_srcu, idx); ret = dcache_dir_open(inode, file); -- 2.43.0
